The Redback Impedance Meter is an absolute necessity for all PA
system installers. An impedance meter is critical for
accurately measuring low impedance loudspeaker systems,
incorporating multiple speakers and crossovers, and for measuring
commercial 70V or 100V line speaker systems, which may include many
speakers with line transformers and several hundred
meters of cable. Trying to measure this type of load is virtually
impossible with a standard multimeter.